The VW Beetle is the most beginner-friendly classic to restore and also the most deceptive. The simplicity is real: air-cooled four-cylinder, no radiator, no power steering, no power brakes in the early cars. But the rust is endemic and it hides in places that are deeply inconvenient to access.

Floor pans are the obvious one. Everybody knows about floor pans. What gets people is the heater channels — the structural box sections that run along the bottom of the car and double as the heating system. When those rot, the car loses significant torsional stiffness. Replacement is not optional.

Get under every Beetle you're considering buying. Poke the heater channels with a screwdriver. If the screwdriver goes through, walk away.